* "all remaining columns", only applicable to the last field), a format
* specifying character ('x' hexadecimal, 'o' octal, 'b' binary, 'l'
* single-bit logic), and an optional bit count (translating to: logic
- * channels communicated in that column). This "column_formats" option
- * is most versatile, other forms of specifying the column layout only
- * exist for backwards compatibility.
+ * channels communicated in that column). The 'a' format marks analog
+ * data, an optionally following number is the digits count (resolution).
+ * The 't' format marks timestamp values, which could help in automatic
+ * determination of the input stream's samplerate. This "column_formats"
+ * option is most versatile, other forms of specifying the column layout
+ * only exist for backwards compatibility, and are rather limited. They
+ * exclusively support logic input data in strictly adjacent columns,
+ * with further constraints on column layout for multi-bit data.
*
* single_column: Specifies the column number which contains the logic data
* for single-column mode. All logic data is taken from several bits
* - ... -I csv:start_line=20:header=yes:...
* Skip the first 19 text lines. Use line 20 to derive channel names.
* Data starts at line 21.
+ * - ... -I csv:column_formats=*a6 ...
+ * Each column contains an analog value with six significant digits
+ * after the decimal period.
+ * - ... -I csv:column_formats=t,2a ...
+ * The first column contains timestamps, the next two columns contain
+ * analog values. The capture's samplerate could get determined from
+ * the timestamp values if not provided by the user by means of the
+ * 'samplerate' option. This assumes a mere number in units of seconds,
+ * and equidistant rows, there is no fancy support for textual unit
+ * suffixes nor gaps in the stream of samples nor other non-linearity,
+ * just '-' ignore the column if the format is not supported).
*/
/*
* TODO
*
- * - Extend support for analog input data? (optional)
+ * - Extend support for analog input data.
* - Determine why analog samples of 'double' data type get scrambled
* in sigrok-cli screen output. Is analog.encoding->unitsize not
* handled properly? A sigrok-cli or libsigrok (src/output) issue?
+ * - Reconsider the channel creation after format processing. Current
+ * logic may "bleed" channel names into the analog group when logic
+ * channels' columns follow analog columns (seen with "-,2a,x8").
+ * Trying to sort it out, a naive change used to map logic channels'
+ * data to incorrect bitmap positions. The whole channel numbering
+ * needs reconsideration. Probably it's easiest to first create _all_
+ * logic channels so that they have adjacent numbers starting at 0
+ * (addressing logic bits), then all analog channels (again adjacent)
+ * to simplify the calculation of their index in the sample set as
+ * well as their sdi channel index from the "analog column index".
* - Optionally get sample rate from timestamp column. Just best-effort
* approach, not necessarily reliable. Users can always specify rates.
* - Add a test suite for input modules in general, and CSV in specific?
FORMAT_HEX, /* Hex digits for a set of bits. */
FORMAT_OCT, /* Oct digits for a set of bits. */
FORMAT_ANALOG, /* Floating point number for an analog channel. */
+ FORMAT_TIME, /* Timestamps. */
};
static const char *col_format_text[] = {
[FORMAT_HEX] = "hexadecimal",
[FORMAT_OCT] = "octal",
[FORMAT_ANALOG] = "analog",
+ [FORMAT_TIME] = "timestamp",
};
static const char col_format_char[] = {
[FORMAT_HEX] = 'x',
[FORMAT_OCT] = 'o',
[FORMAT_ANALOG] = 'a',
+ [FORMAT_TIME] = 't',
};
+static gboolean format_is_ignore(enum single_col_format fmt)
+{
+ return fmt == FORMAT_NONE;
+}
+
+static gboolean format_is_logic(enum single_col_format fmt)
+{
+ return fmt >= FORMAT_BIN && fmt <= FORMAT_OCT;
+}
+
+static gboolean format_is_analog(enum single_col_format fmt)
+{
+ return fmt == FORMAT_ANALOG;
+}
+
+static gboolean format_is_timestamp(enum single_col_format fmt)
+{
+ return fmt == FORMAT_TIME;
+}
+
struct column_details {
size_t col_nr;
enum single_col_format text_format;
size_t channel_offset;
size_t channel_count;
+ size_t channel_index;
int analog_digits;
};
struct context {
gboolean started;
- /* Current selected samplerate. */
+ /* Current samplerate, optionally determined from input data. */
uint64_t samplerate;
+ double prev_timestamp;
gboolean samplerate_sent;
/* Number of channels. */
case 'a':
format_code = FORMAT_ANALOG;
break;
+ case 't':
+ format_code = FORMAT_TIME;
+ break;
default: /* includes NUL */
return SR_ERR_ARG;
}
if (!endp)
return SR_ERR_ARG;
if (endp == spec)
- count = (format_code == FORMAT_ANALOG) ? 3 : 1;
- if (!format_code)
+ count = format_is_analog(format_code) ? 3 : 1;
+ if (format_is_ignore(format_code))
count = 0;
if (format_char == 'l')
count = 1;
c = auto_column_count;
}
column_count += c;
- if (f == FORMAT_ANALOG)
+ if (format_is_analog(f))
analog_count += c;
- else if (f)
+ else if (format_is_logic(f))
logic_count += c * b;
}
sr_dbg("Column format %s -> %zu columns, %zu logic, %zu analog channels.",
detail = &inc->column_details[column_idx++];
detail->col_nr = column_idx;
detail->text_format = f;
- if (detail->text_format == FORMAT_ANALOG) {
+ if (format_is_analog(detail->text_format)) {
detail->channel_offset = analog_idx;
detail->channel_count = 1;
detail->analog_digits = b;
analog_idx += detail->channel_count;
- } else if (detail->text_format) {
+ } else if (format_is_logic(detail->text_format)) {
detail->channel_offset = channel_idx;
detail->channel_count = b;
channel_idx += detail->channel_count;
- }
- sr_dbg("detail -> col %zu, fmt %s, ch off/cnt %zu/%zu",
- detail->col_nr, col_format_text[detail->text_format],
- detail->channel_offset, detail->channel_count);
- if (!detail->text_format)
+ } else if (format_is_ignore(detail->text_format)) {
+ /* EMPTY */
continue;
+ } else {
+ /*
+ * Neither logic nor analog data, nor ignore.
+ * Format was noted. No channel creation involved.
+ */
+ continue;
+ }
/*
- * Create channels with appropriate names. Optionally
+ * Pick most appropriate channel names. Optionally
* use text from a header line (when requested by the
* user). In the absence of header text, channels are
* assigned rather generic names.
caption = NULL;
if (!caption || !*caption)
caption = NULL;
+ /*
+ * TODO Need we first create _all_ logic channels,
+ * before creating analog channels? Just store the
+ * parameters here (index, type, name) and have the
+ * creation sequence done outside of the format
+ * spec parse loop.
+ */
for (create_idx = 0; create_idx < detail->channel_count; create_idx++) {
if (caption && detail->channel_count == 1) {
g_string_assign(channel_name, caption);
g_string_printf(channel_name, "%zu",
detail->channel_offset + create_idx);
}
- if (detail->text_format == FORMAT_ANALOG) {
+ if (format_is_analog(detail->text_format)) {
channel_sdi_nr = logic_count + detail->channel_offset + create_idx;
channel_type = SR_CHANNEL_ANALOG;
- } else {
+ detail->channel_index = g_slist_length(in->sdi->channels);
+ } else if (format_is_logic(detail->text_format)) {
channel_sdi_nr = detail->channel_offset + create_idx;
channel_type = SR_CHANNEL_LOGIC;
+ } else {
+ continue;
}
sr_channel_new(in->sdi, channel_sdi_nr,
channel_type, TRUE, channel_name->str);
ch_rem--;
set_logic_level(inc, ch_idx + 0, bits & (1 << 0));
break;
- case FORMAT_ANALOG:
- case FORMAT_NONE:
+ default:
/* ShouldNotHappen(TM), but silences compiler warning. */
return SR_ERR;
}
csv_analog_t value;
int ret;
- if (details->text_format != FORMAT_ANALOG)
+ if (!format_is_analog(details->text_format))
return SR_ERR_BUG;
length = strlen(column);
return SR_OK;
}
+/**
+ * @brief Parse a timestamp text, auto-determine samplerate.
+ *
+ * @param[in] column The input text, a floating point number.
+ * @param[in] inc The input module's context.
+ * @param[in] details The column processing details.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR Invalid input data (empty, or format error).
+ *
+ * This routine attempts to automatically determine the input data's
+ * samplerate from text rows' timestamp values. Only simple formats are
+ * supported, user provided values always take precedence.
+ */
+static int parse_timestamp(const char *column, struct context *inc,
+ const struct column_details *details)
+{
+ double ts, rate;
+ int ret;
+
+ if (!format_is_timestamp(details->text_format))
+ return SR_ERR_BUG;
+
+ /*
+ * Implementor's notes on timestamp interpretation. Use a simple
+ * approach for improved maintainability which covers most cases
+ * of input data. There is not much gain in adding complexity,
+ * users can easily provide the rate when auto-detection fails.
+ * - Bail out if samplerate is known already.
+ * - Try to interpret the timestamp (simple float conversion).
+ * If conversion fails then clear all previous knowledge and
+ * bail out (non-fatal, perhaps warn). Silently ignore values
+ * of zero since those could be silent fails -- assume that
+ * genuine data contains at least two adjacent rows with useful
+ * timestamps for the feature to work reliably. Annoying users
+ * with "failed to detect" messages is acceptable here, since
+ * users expecting the feature to work should provide useful
+ * data, and there are easy ways to disable the detection or
+ * ignore the column.
+ * - If there is no previous timestamp, keep the current value
+ * for later reference and bail out.
+ * - If a previous timestamp was seen, determine the difference
+ * between them, and derive the samplerate. Update internal
+ * state (the value automatically gets sent to the datafeed),
+ * and clear previous knowledge. Subsequent calls will ignore
+ * following input data (see above, rate is known).
+ *
+ * TODO Potential future improvements:
+ * - Prefer rationals over floats for improved precision and
+ * reduced rounding errors which result in odd rates.
+ * - Support other formats ("2 ms" or similar)?
+ */
+ if (inc->samplerate)
+ return SR_OK;
+ ret = sr_atod_ascii(column, &ts);
+ if (ret != SR_OK)
+ ts = 0.0;
+ if (!ts) {
+ sr_warn("Cannot convert timestamp text %s in line %zu (or zero value).",
+ column, inc->line_number);
+ inc->prev_timestamp = 0.0;
+ return SR_OK;
+ }
+ if (!inc->prev_timestamp) {
+ sr_dbg("First timestamp value %g in line %zu.",
+ ts, inc->line_number);
+ inc->prev_timestamp = ts;
+ return SR_OK;
+ }
+ sr_dbg("Second timestamp value %g in line %zu.", ts, inc->line_number);
+ ts -= inc->prev_timestamp;
+ sr_dbg("Timestamp difference %g in line %zu.",
+ ts, inc->line_number);
+ if (!ts) {
+ sr_warn("Zero timestamp difference in line %zu.",
+ inc->line_number);
+ inc->prev_timestamp = ts;
+ return SR_OK;
+ }
+ rate = 1.0 / ts;
+ rate += 0.5;
+ rate = (uint64_t)rate;
+ sr_dbg("Rate from timestamp %g in line %zu.", rate, inc->line_number);
+ inc->samplerate = rate;
+ inc->prev_timestamp = 0.0;
+
+ return SR_OK;
+}
+
/**
* @brief Parse routine which ignores the input text.
*
[FORMAT_OCT] = parse_logic,
[FORMAT_HEX] = parse_logic,
[FORMAT_ANALOG] = parse_analog,
+ [FORMAT_TIME] = parse_timestamp,
};
static int init(struct sr_input *in, GHashTable *options)
{
struct context *inc;
size_t num_columns;
- size_t line_number, line_idx, ch_idx;
+ size_t line_number, line_idx;
int ret;
char **lines, *line, **columns;
* for datafeed submission that is a multiple of the unit size.
* Allocate the larger buffer, the "sample buffer" will point
* to a location within that large buffer later.
+ *
+ * TODO Move channel creation here, and just store required
+ * parameters in the format parser above? Could simplify the
+ * arrangement that logic and analog channels get created in
+ * strict sequence in their respective groups.
*/
if (inc->logic_channels) {
inc->sample_unit_size = (inc->logic_channels + 7) / 8;
if (inc->analog_channels) {
size_t sample_size, sample_count;
size_t detail_idx;
+ struct column_details *detail;
int *digits_item;
+ void *channel;
sample_size = sizeof(inc->analog_datafeed_buffer[0]);
inc->analog_datafeed_buf_size = CHUNK_SIZE;
inc->analog_datafeed_buf_size /= sample_size;
goto out;
}
inc->analog_datafeed_buf_fill = 0;
- inc->analog_datafeed_channels = g_malloc0_n(inc->analog_channels, sizeof(inc->analog_datafeed_channels[0]));
- for (ch_idx = 0; ch_idx < inc->analog_channels; ch_idx++) {
- void *channel;
- channel = g_slist_nth_data(in->sdi->channels, inc->logic_channels + ch_idx);
- inc->analog_datafeed_channels[ch_idx] = g_slist_append(NULL, channel);
- }
+ inc->analog_datafeed_channels = g_malloc0(inc->analog_channels * sizeof(inc->analog_datafeed_channels[0]));
inc->analog_datafeed_digits = g_malloc0(inc->analog_channels * sizeof(inc->analog_datafeed_digits[0]));
digits_item = inc->analog_datafeed_digits;
for (detail_idx = 0; detail_idx < inc->column_want_count; detail_idx++) {
- if (inc->column_details[detail_idx].text_format != FORMAT_ANALOG)
+ detail = &inc->column_details[detail_idx];
+ if (!format_is_analog(detail->text_format))
continue;
- *digits_item++ = inc->column_details[detail_idx].analog_digits;
+ channel = g_slist_nth_data(in->sdi->channels, detail->channel_index);
+ inc->analog_datafeed_channels[detail->channel_offset] = g_slist_append(NULL, channel);
+ *digits_item++ = detail->analog_digits;
}
}
static struct sr_option options[] = {
[OPT_COL_FMTS] = {
"column_formats", "Column format specs",
- "Specifies text columns data types: comma separated list of [<cols>]<fmt>[<bits>], with -/x/o/b/l format specifiers.",
+ "Specifies text columns data types: A comma separated list of [<cols>]<fmt>[<bits>] items, with - to ignore columns, x/o/b/l for logic data, a (and resolution) for analog data, t for timestamps.",
NULL, NULL,
},
[OPT_SINGLE_COL] = {
"single_column", "Single column",
- "Enable single-column mode, exclusively use text from the specified column (number starting at 1).",
+ "Enable single-column mode, exclusively use text from the specified column (number starting at 1). Obsoleted by 'column_formats'.",
NULL, NULL,
},
[OPT_FIRST_COL] = {
"first_column", "First column",
- "Number of the first column with logic data in simple multi-column mode (number starting at 1, default 1).",
+ "Number of the first column with logic data in simple multi-column mode (number starting at 1, default 1). Obsoleted by 'column_formats'.",
NULL, NULL,
},
[OPT_NUM_LOGIC] = {
},
[OPT_FORMAT] = {
"single_format", "Data format for simple single-column mode.",
- "The number format of single-column mode input data: bin, hex, oct.",
+ "The number format of single-column mode input data: bin, hex, oct. Obsoleted by 'column_formats'.",
NULL, NULL,
},
[OPT_START] = {
},
[OPT_HEADER] = {
"header", "Get channel names from first line.",
- "Use the first processed line's column captions (when available) as channel names.",
+ "Use the first processed line's column captions (when available) as channel names. Off by default",
NULL, NULL,
},
[OPT_RATE] = {
"samplerate", "Samplerate (Hz)",
- "The input data's sample rate in Hz.",
+ "The input data's sample rate in Hz. No default value.",
NULL, NULL,
},
[OPT_DELIM] = {
},
[OPT_COMMENT] = {
"comment_leader", "Comment leader character",
- "The text which starts comments at the end of text lines.",
+ "The text which starts comments at the end of text lines, semicolon by default.",
NULL, NULL,
},
[OPT_MAX] = ALL_ZERO,
projects / libsigrok.git / blobdiff